Intermittent pressure mechanism for type-impression devices



INTERMITTENT PRESSURE MECHANISM FOR TYPE IMPRESSION DEVICES Jan. 3, 1928. I

-. W. H. SINCLAIR 2 Sheets-Sheet 1 Filed Aug. 28. l926 m wsw attorney:

' Jan. 3, 1928.

w. H. SINCLAIR INTERMITTENT PRESSURE MECHANISM FOR TYPE IMPRESSION DEVICES Filed Aug. 28, 1926 2 Sheets-Sheet 2 fiiven 01". %,%m y flaw (Iflarn eys.

Patented Jan. 3, 1928.

w'IL 'IAivI n. S NC A R, or BERKELEY, oAnIroRiviAfAssie ioamo Q L f PRESSIONS oORroRATIOn, OF CARSON CITY, NEVADA, A CORPORATION OF NEVADA.

INTERMITTRNT PRESSURE MECHAhTISlYI FOR TYPRIMPRR'SSION DEVICES;

Application filed August 28, 1926. Sean Nbf 132,070}

My inventionrelates generally'to type-limpression devices and especially to machines employing a platen and type-impact bars, each of the latter carrying plural. characters individually distinguishable, and which are termed upper case and lower case. These terms refer in a special sense to capitals?- and small letters respectively; and while, it is true, such classification comprises the greater number of type used, many bars carry plural type-characters not necessarily falling strictly within said terms. Forthe' sake of simplicity, how-ever, I shall herein use these terms as indicative of relative po-' sitions on the bars, without regard to the nature of the characters occupying such positions. V

Typewriters may be taken as illustrative herein of the class of type-impression de vices with which my invention s especially concerned. In some of thesemachines, a vertical movement of the platen is provided to selectively change the priiitmg'line on the work as I shall herein term the sheet or sheets passing through the machine in Order to present said line; to the point of type impact of one or the other of the plural characters on the typebar; and in other machines the necessary variation is made bya vertical movement bodily of the type-bar basket.

There-are other expedients for this purpose,

but the above noted are sufficient to illustrate the diiiiculty which it is the object of my invention to avoid. v r

This difrlculty is the objectionable feature of the simultaneous impact. of both upper and lower case type, one in full and the other in part impression, resulting iii a perfect line of printed characters onthe work anda blurred, more or'less indistinct line parallel with the first line, which is confi'isingan'd at best is unsightly and lacking in neatness.

The essential reason for this undesirable result is the imperfect flattening of the work in the printing line; and though a pressei bar or paper finger or guides are usually associated with the platen to hold saidwor'k as close as possible, these are necessarily rela-,

This is the case even when single record sheets comprise the work, and be due to wear and tear or faulty adjustment or manipulation;fbut when manifolding is in progress and the work comprises a plurality of individuals, both record and transfer sheets or members, it is obvious that the resulting thickness can only accentuate the failure of close contact or flatness and the consequent bulging.

While the ditliculty under consideration is thus seen even in ordinary machines, and in the customary work thereof, I have still to point out a problem inherent in theiise' and operation of a special type of machine, and in the solutionof which my'inv'ention may. be said to reach its highest development and utility; l I refer to'those man'ifoldin'g typewriters in which one or more manifolding memberslie between the record sheets and have an oscillating or other movementimparted 11013116111" independently of the record sheets, for the purposeof causing their entire surface to be usedin transferring function, In such workassemblages, freedom for the independent movements of said manifoldingmembers is essential, and even the customary presser bars or fingers are restrictiveof this freedom. To retain this necessaryfreedom andyet provide for a closeor flattened contact of the composite work with the platen is possible with my invention, as will hereinafter appear. v r V Briefly stated and in its broadest aspect my invention comprises means forfflattening the work in the printingline in the immediate vicinity 'of the point of type impact just prior to impact, and innnediately thereaftei frelieving said pressure.

In its best form said means are automatic in operation, and, in pract ce are inade dependent upon the key-actuat on of the typebar.. Furthermorein. .its most acceptable form said means are associated either as in tegra1..with or as carried by the vertically reciprocating ribbon-j umpen Of the center guidewhich alternatelypresents and With-' draws the ribbon to and from the line of type impact. 1 1

The natureiofimy invention in its preferred form-will now be fully'described -by referencelto the accompanying: drawings it being'understood that changes may be made Within the scope of the claims hereunto appended, without departing from the spirit of the invention.

Fig. 1 is a front view, chiefly diagranr lnatic, and indicating such parts of a typical typewriter as are required for reference in describing my invention.

Fig. 2 is a fragmentary face view of a printed sheet of the work showing the complete impression of the upper case type and the underlying impression of a part of the lower case type, an effect which, as above stated, it is the object of my invention to obviate.

Fig. 3 is a side view of the upper end of a type-bar indicating the upper and lower case type carried thereby.

Fig. 4 is a front elevation of the usual center-guide, showing the reciprocative ribhon-jumper (through which the ribbon is threaded in its depressed position, which provides, as is customary, for making the impressions visible.

Fig. 5 is a view similar to Fig. t but showing the ribbon-jumper. elevated to the printing line just prior to type impact.

Fig. 6 is a sectional detail, showing the ribbon-jumper depressed, and, indicating the relation, to the platen, of my intermittent pressure member carried by said jumper.

Fig. 7 is a rear elevation, enlar 'ed, of my intermittent pressure member.

Fig. 8 is a perspective view, from the rear, of the improved intermittent pressure mechanism comprising the assembled center" guide, ribbon-jumper and pressure member. Fig. 9 is a diagrammatic sectlonal detail showing the relation of the platen, they work, and the pressure member, when the pressure is relieved, and indicating the necessary freedom in such relation.

Fig. 10 is a diagrammatic detail showing the relation of the parts of Fig. 9, when said pressure member is active. 7

Referringto Fig. 1, the numeral lindicates the frame of a typewriter, 2 the cylindrical platen, 3 the paper-table, 4. the type-bar basket, 5 one of the type-bars, 6 the center-guide, 7 the ribbon-jumper'car ried by said center guide, 8 the ribbon threaded through the jumper and S the ribbon spools.

As indicated in Fig. .3, the free end of the type-bar 5 carries plural type in alignment longitudinally 'of the bar, the outermost,

represented by 9 being usually upper case and the inner one, 10, being lower case, as for example, capitals 1n the first instance and small letters 1n the second instance, or

any other different characters usually-era" ployed and positioned in alignment.

For several reasons, and under a variety of circumstances, it not infrequently happens that' when the shift is made to print from either case type, a portion of the other case type also reaches the work, re: sulting in an unsightly blurring. This is shown in Fig. 2 in which 11 indicates the work or sheet to be printed upon, the upper case type impressions 9 being perfect, and the lower case type impressions 10 incomplete. 7

It is common practisein typewriters to carry the ribbon to the printing line immediately before the type impact, and to withdraw it immediately after said impact so that the impression becomes visible. This is the function of the ribbonjumper 7 through which the ribbon isthreaded, and is illustrated in Figs. 4 and 5. The center guide 6 is a fixed plate and the ribbon-jumper 7 'is mounted for linear reciprocationupon said guide.

I have not deemed it necessary to show the.

transn'iitting connections by which the movement of the ribbon-pimper is effected by suitable association with the'operating keys of the machine. It is suiiicient to indicate by the lever 12 of Fig. 8 the terminal member of said connections.

In Fig. 4 the depressed position of the ribbon-jumper relatively to the printing line, indicated by the row of numerals, shows the reason for the withdrawal of the ribbon namely, to make them visible. In Fig. 5 the elevation of the ribbon-jumper shows the covering of the printing line by the ribbon, in order to receive the type impact. Thus far the description and illustration have been directed to common practice,and

I deem it advisable, before proceeding to.

specifically disclose my improvement, to point out the problems involved in this common pract1ce,winch 1t 1s the object of my invention to solve.

Manife'stly the absolute flattening out of the work against'the platen, in the printing line, is the theoretical condition for perfect impression. Any bulging or looseness of the work is destructive of such impression. Paper guides in a variety of forms and positions are used to holdthe work as flat as possible upon the platen, and these have been located as near as may be, above or below, to the printing line, but not in said line since such position would interfere'with visible writing in thatthey would cover up the nnpressions previously made 111 the line. Therefore, even where thework consists of a single sheet, it may and often doesjl'iappen that there will be a looseness orlack of flatness in the sheet in the'l ne of type impact,

a slight bulge in fact, sufiicient in extent to cause aportion of the lower case type to im-' press it, in addition to the desired img'irese sion of the upper case. This undesirable result is all the more likely to happen if the work comprises a plurality of sheets, as for, example inmanifold 1ng,,for in that case the tlncknessotthe work and its composit on as separate units.

renders it quite likely at the printing. line to be loose both inherently and with relation to the platen.

While, even .in the ordinary work and with; the common typeset .machines as'I' have just explained, there is a necessity fora means for; intermittently holdingthe work fiatin the printing line and in the .immedi ate VlClIiltY Of the point} of type impact,:and at the time of the impact, and of withdraw such necessity is present with greater insistence in those forms of machines especially adapted'for manifolding inwhich the manifolding' members'lying between the paper sheets h ave movements imparted to them whichare independent of said-sheets, as for example, a,travelof.said' nembers or an oscillation eitheiv'longitudinalor transverse or both, to provide for utilizing substantially their entire surface area.

independent movement of the manifolding members is imperative, in, order to provide suiiicient freedom or loosenessbetween, the work components to, enables-aid movements to be made-without undue friction or blur ring tendency, All the termsofthese-problems aresolvable in practice by the. simple but ,eifective expedient ot'carrying the intermittentpressure means upon. the reciproca tive ribbonumper.

Referring now to Figs. 7 and 8, and particularlythe latter, l3 isthe pressure device or member. It consists of a pair'of spaced members on the rear face of the-ribbon jumper 7, oneon each sideo tand in theline of theopemng 7 of said umper through which the type strikes. In the form shown these members are strips secured :to the ribbon umper, and are yielding; ones, due-t0 having resilient head bends 13.

The relation oftheimproved jumper as-;

sembly to the platen is shown in Fig. 6; and the effect of the pressure member13 is well illustrated in F igs. 9 and 10;

In Fig. 9 the pressure member 13 is shown in its retracted or withdrawn position, wherein it is clear of the work 11-and-the latter is shown as capable of presenting its written line to view, and as having a freedom from pressuresuificient for the movements of any of its components.

In Fig. 10 the pressuremember 13 has.

moved up and into contact with the work, and has pressed it flatagainst thelplaten ready to receive the type impact.

The operation, briefly, maynow be stated.

The normal position of the ribbon-jumper and ribbon is down, so that the printing line on the worlris in sight. As a keyis pressed and. the type. bar begins to rise, the: ribbon mg such means to render the writingcvisible,"

In such machines the relief from pressure at the time of sai-l jumper also rises-and carries the ribbon to and 1n=front of the printing. line, and also line for visibility, and also carrying the-' pressure strips 13 away from contact with the work, so that-the latter is free enough to permit the independent? movements 0t any manifoldin-gmembers which may be in use.

' Although I have hereinbefore, in referring to the blurring of :tlie work, somewhat briefly mentionedits causes, I deem it well topoint out other considerations having direct bearmgnpon the utility ot my invention in obviating the undesirable result of causes inherent in the problem, and which are either in addition to or aggravate the im-' mediate cause, namely the imperfect relation 7 of the work to. the impact surface of the platen, as" manifest in the bulging of the work; This is especially pertinentto platens as ordinarily employed with loose sheets of carbon paper.

The type carried on the ends of the bars are'manufactured with a certain are or curve extending from the limits of the upper to the lower case. a

This arc or curve is a previously determined one,and isdesigned to. coordinate with thezimaginary are or curve of the rubber sheath 'forminglthe: periphery of the platen.

hen this r'ubber s'heath is newly made of' fresh rubber, it is ground to a certain diameter to correspond in arc to the curve on the face of the type characters whose impact it is designed to receive intrue relationship;

The are! of the type remains' a constant in theory,- due to the nature of the material composingit, assuming normal operative pressure and continuity of clean type. Howey er, as hereinafter pointed out, this are also becomes a variable. The character of the material composing the sheath is such that both the wear upon it and the chemical action'which 'efiie'cts'it from vulcanization etc.-, make ita variable in diamter, and consequently in arc. 0t:accommodating'or adjusting the position of the record sheets and copying medium be tween a constant arc and a variable arc, or

ad usting record more correctly stated, sheets and copying medium'between-two' va riable. arcs of contactwith saidrec'ord sheets Thus there is the problem and copying medium; so as to avoid blurring. It is obvious that some supplemental agency must become operative or the results will not be uniform, and as the changes occur, the result must otherwise be distorted. Such is the case. ment or accommodation is made in a new typewriter, as the platen recedes in diameter, the blurring gradually begins to take place, and is manifested in a line .below or above the typed one, as though it were a continuous series of merged dots. This line is really formed by the tips of the other case of letters or characters, resulting from the distorted position of the work due to the changed diameter of the platen.

It will be apparent that this condition is gradual. and that the remedy for this changing condition, must be automatic in charac ter. My lllVCIltlOi'l is thus automatic and prevents the work from bulging or assuming a distorted position with relation to the other case type than the one intended to be employed, arising from changing platen diameter. While it may be possible to bend the type to properly correspond to the changing diameter of the platen, this invention. does away with that necessity. I

The next point to he mentioned in this connection, is the fact that my invention automatically corrects the blurring arising from distortion of the arc of the type due to undue pressure from improper pounding of the keys, as well as the normal wear on the type. This, it will be noted increases the degree ofv the are on the outside of the work, instead of decreasing it underneath the work.

Still another very common and frequent cause of this blurring line previously re.- ferred to. is the failure of the stenographer to clean the type, that is to keep them clean. The result of this failure is that both dirt and ink, and lint from the original copy ribbon accumulate on the face of the type. This added thickness changes the true theoretical coordination of the arcs of the type and platen, because it will be quite plain that this added thickness is not uniform on all the type or characters takencollectively relatively. An analysis of the result is that there islirst a constantly changing individual are on the outside of the Work, that is, the record sheets and copying medium, as well as underneath the same. The paper guides on the machines of today merely serve to conform the work to the general contour oi the platen. My invention has a special object as a paper guide in conforming the work to variations in the arc of the platen with those of each individual type, in a 'manner to avoid blurring on the work. Second, and more important, the accretions on the type lengthen the contact length of the are, and tend to partially close up, the

Even if perfect adjust-' opening between the type characters, thus exaggerating the tendency to the blurring contact whichthe exactly calculated theoretical opening was measured'to avoid if the type were clean.

It will now be seen from the problem hereinand the disclosure of a practical means for solving it, that all the elements necessary to a solution are known and successively considered. For example, the type bar with the type located at one extremity thereof, forms a lever with a striking head. It is so constructed because the nature of the result sought is a violent one, that'is, one characterized by great physical force, the

object being to impress or imprint. The ele ments necessary for the objects of this invention are such'asto produce the reverse of this result. lVhile the action of the mechanism must be swift in approach and recession, the actual contact resulting 'must be so gentle in action and motion as to result in a degree of impingement less than impact. The nature of the mechanism, while operat ing intimel y relation to the swift movement of the type, must be of a form and movement to mitigate what would otherwise become an impact. The movement must be gentle in action and motion; the contact must be soft and easily yielding to pressure, although swift; somewhat in the nature of a wiping contact. If the form of the contact member were not such that the contact was distributed over a suflicient contact area, it would be either a very ditlicult or impossible problem to supply the elements of motion which would avoid the very result the invention is intended to eliminate. In other words,

if the contactmember were concentrated to a point, it would tremendously increase the requirements for the elements of motion necessary to avoid an imprint. This invention is of such a form, and the movementsof such a character as to form a combination capable of attaining. the results necessary to meet all the terms of the problem.

I claim 1. In a type impression machine and in combination with its reciprocative ribbon jumper adapted to carry the printing ribbon to and from the printing line of thework in the machine, a member reciprocating in unison with said ribbon-jumper adapted to impose flattening pressure upon and reliev ing said work in the printing-line in timely accord with the impending and completed type impact, respectively. 1

'2. In a type impression machine 'andin combination with its reciprocative ribbonjumper adapted to carry the printing ribbon to and from the printing line of'the work in the machine, a memberreciprocating in unison with said ribbon-jumper and positioned relatively thereto adaptingit toimpose flattening pressure upon and relieving said work in the printing line adjacent the point of type-impact in timely accord with the impending and completed type impact, respectively.

3. In a type impression machine and in combination with its reciprocative ribbonjumper adapted to carry the printing ribbon to and from the printing line of the work in the machine, a member carried by said ribbon-jumper in position adapting it to impose and relieve flattening pressure upon the work in the printing line in timely accord with the impending and completed type impact.

4. In a type impression machine and in combination With its reciprocative ribbonjumper adapted to carrythe printing ribbon to and from the printing line of the work in the machine, a resilient member carried by Y said ribbonjumper in position adapting it to impose and relieve a yielding flattening pressure upon the work, in the printing line. in timely accord with the impending and completed type impact. Y 7

5. In a type impression machine and in combination with its reciprocative ribbonjumper adapted to carry the printing ribbon to and from the printing line of the Work in the machine, a strip on the inner face of said jumper adapted to impose intermittent pressure upon said work in the printing linein timely accord with the impending and completed type impact.

6. In a type impression machine and in combination with its reciprocative ribbonjumper adapted to carry the printing ribbon to and from the printing line of the work in the machine a strip on the inner face of the said jumper, said strip having a resilient end adapted to impose. intermittent pressure upon said Work in the printing line in-timely accord with the impending and completed type impact.

7. In a type impression machine and in combination with its reciprocative ribbonjuinper adapted to carry the printing ribbon to and from the printing line of the work in the machine a pair of spaced strips on the inner face of said jumper, adapted to impose intermittent pressure upon the work in the printing line on each side of the point of type impact, and in timely accord with the impending and completed type impact.

8. In a type impression machine and in combination with its reciprocative ribbonjumper adapted to carry the printing ribbon to and from the printing line of the work in the machine a pair of spaced strips on the inner face of said jumper, said strips having a resilient end adapted to impose intermittent pressure upon the Work in the printing line on each side of the point of type impact, and in timely accord with the.

impending and completed: type impact.

' In testimony whereof I have signed my name to this specification.

' WILLIAM H. SINCLAIR. 

